digi_acceleport.c

linux 内核源代码

	unsigned long flags = 0;

	dbg("digi_close: TOP: port=%d, open_count=%d",
		priv->dp_port_num, port->open_count);

	/* if disconnected, just clear flags */
	if (!usb_get_intfdata(port->serial->interface))
		goto exit;

	/* do cleanup only after final close on this port */
	spin_lock_irqsave(&priv->dp_port_lock, flags);
	priv->dp_in_close = 1;
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);

	/* tell line discipline to process only XON/XOFF */
	tty->closing = 1;

	/* wait for output to drain */
	if ((filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0)
		tty_wait_until_sent(tty, DIGI_CLOSE_TIMEOUT);

	/* flush driver and line discipline buffers */
	if (tty->driver->flush_buffer)
		tty->driver->flush_buffer(tty);
	tty_ldisc_flush(tty);

	if (port->serial->dev) {
		/* wait for transmit idle */
		if ((filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0) {
			digi_transmit_idle(port, DIGI_CLOSE_TIMEOUT);
		}
		/* drop DTR and RTS */
		digi_set_modem_signals(port, 0, 0);

		/* disable input flow control */
		buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
		buf[1] = priv->dp_port_num;
		buf[2] = DIGI_DISABLE;
		buf[3] = 0;

		/* disable output flow control */
		buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
		buf[5] = priv->dp_port_num;
		buf[6] = DIGI_DISABLE;
		buf[7] = 0;

		/* disable reading modem signals automatically */
		buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
		buf[9] = priv->dp_port_num;
		buf[10] = DIGI_DISABLE;
		buf[11] = 0;

		/* disable receive */
		buf[12] = DIGI_CMD_RECEIVE_ENABLE;
		buf[13] = priv->dp_port_num;
		buf[14] = DIGI_DISABLE;
		buf[15] = 0;

		/* flush fifos */
		buf[16] = DIGI_CMD_IFLUSH_FIFO;
		buf[17] = priv->dp_port_num;
		buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
		buf[19] = 0;

		if ((ret = digi_write_oob_command(port, buf, 20, 0)) != 0)
			dbg("digi_close: write oob failed, ret=%d", ret);

		/* wait for final commands on oob port to complete */
		prepare_to_wait(&priv->dp_flush_wait, &wait, TASK_INTERRUPTIBLE);
		schedule_timeout(DIGI_CLOSE_TIMEOUT);
		finish_wait(&priv->dp_flush_wait, &wait);

		/* shutdown any outstanding bulk writes */
		usb_kill_urb(port->write_urb);
	}
	tty->closing = 0;
exit:
	spin_lock_irqsave(&priv->dp_port_lock, flags);
	priv->dp_write_urb_in_use = 0;
	priv->dp_in_close = 0;
	wake_up_interruptible(&priv->dp_close_wait);
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
	dbg("digi_close: done");
}


/*
*  Digi Startup Device
*
*  Starts reads on all ports.  Must be called AFTER startup, with
*  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
*/

static int digi_startup_device(struct usb_serial *serial)
{
	int i,ret = 0;
	struct digi_serial *serial_priv = usb_get_serial_data(serial);
	struct usb_serial_port *port;

	/* be sure this happens exactly once */
	spin_lock(&serial_priv->ds_serial_lock);
	if (serial_priv->ds_device_started) {
		spin_unlock(&serial_priv->ds_serial_lock);
		return 0;
	}
	serial_priv->ds_device_started = 1;
	spin_unlock(&serial_priv->ds_serial_lock);

	/* start reading from each bulk in endpoint for the device */
	/* set USB_DISABLE_SPD flag for write bulk urbs */
	for (i = 0; i < serial->type->num_ports + 1; i++) {
		port = serial->port[i];
		port->write_urb->dev = port->serial->dev;
		if ((ret = usb_submit_urb(port->read_urb, GFP_KERNEL)) != 0) {
			err("%s: usb_submit_urb failed, ret=%d, port=%d",
					__FUNCTION__, ret, i);
			break;
		}
	}
	return ret;
}


static int digi_startup(struct usb_serial *serial)
{

	int i;
	struct digi_port *priv;
	struct digi_serial *serial_priv;

	dbg("digi_startup: TOP");

	/* allocate the private data structures for all ports */
	/* number of regular ports + 1 for the out-of-band port */
	for(i = 0; i < serial->type->num_ports + 1; i++) {
		/* allocate port private structure */
		priv = kmalloc(sizeof(struct digi_port), GFP_KERNEL);
		if (priv == NULL) {
			while (--i >= 0)
				kfree(usb_get_serial_port_data(serial->port[i]));
			return 1;			/* error */
		}

		/* initialize port private structure */
		spin_lock_init(&priv->dp_port_lock);
		priv->dp_port_num = i;
		priv->dp_out_buf_len = 0;
		priv->dp_write_urb_in_use = 0;
		priv->dp_modem_signals = 0;
		init_waitqueue_head(&priv->dp_modem_change_wait);
		priv->dp_transmit_idle = 0;
		init_waitqueue_head(&priv->dp_transmit_idle_wait);
		priv->dp_throttled = 0;
		priv->dp_throttle_restart = 0;
		init_waitqueue_head(&priv->dp_flush_wait);
		priv->dp_in_close = 0;
		init_waitqueue_head(&priv->dp_close_wait);
		INIT_WORK(&priv->dp_wakeup_work, digi_wakeup_write_lock);
		priv->dp_port = serial->port[i];
		/* initialize write wait queue for this port */
		init_waitqueue_head(&serial->port[i]->write_wait);

		usb_set_serial_port_data(serial->port[i], priv);
	}

	/* allocate serial private structure */
	serial_priv = kmalloc(sizeof(struct digi_serial), GFP_KERNEL);
	if (serial_priv == NULL) {
		for (i = 0; i < serial->type->num_ports + 1; i++)
			kfree(usb_get_serial_port_data(serial->port[i]));
		return 1;			/* error */
	}

	/* initialize serial private structure */
	spin_lock_init(&serial_priv->ds_serial_lock);
	serial_priv->ds_oob_port_num = serial->type->num_ports;
	serial_priv->ds_oob_port = serial->port[serial_priv->ds_oob_port_num];
	serial_priv->ds_device_started = 0;
	usb_set_serial_data(serial, serial_priv);

	return 0;
}


static void digi_shutdown(struct usb_serial *serial)
{
	int i;
	dbg("digi_shutdown: TOP, in_interrupt()=%ld", in_interrupt());

	/* stop reads and writes on all ports */
	for (i = 0; i < serial->type->num_ports + 1; i++) {
		usb_kill_urb(serial->port[i]->read_urb);
		usb_kill_urb(serial->port[i]->write_urb);
	}

	/* free the private data structures for all ports */
	/* number of regular ports + 1 for the out-of-band port */
	for(i = 0; i < serial->type->num_ports + 1; i++)
		kfree(usb_get_serial_port_data(serial->port[i]));
	kfree(usb_get_serial_data(serial));
}


static void digi_read_bulk_callback(struct urb *urb)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct digi_port *priv;
	struct digi_serial *serial_priv;
	int ret;
	int status = urb->status;

	dbg("digi_read_bulk_callback: TOP");

	/* port sanity check, do not resubmit if port is not valid */
	if (port == NULL || (priv = usb_get_serial_port_data(port)) == NULL) {
		err("%s: port or port->private is NULL, status=%d",
		    __FUNCTION__, status);
		return;
	}
	if (port->serial == NULL ||
		(serial_priv=usb_get_serial_data(port->serial)) == NULL) {
		err("%s: serial is bad or serial->private is NULL, status=%d",
			__FUNCTION__, status);
		return;
	}

	/* do not resubmit urb if it has any status error */
	if (status) {
		err("%s: nonzero read bulk status: status=%d, port=%d",
		    __FUNCTION__, status, priv->dp_port_num);
		return;
	}

	/* handle oob or inb callback, do not resubmit if error */
	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
		if (digi_read_oob_callback(urb) != 0)
			return;
	} else {
		if (digi_read_inb_callback(urb) != 0)
			return;
	}

	/* continue read */
	urb->dev = port->serial->dev;
	if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) != 0) {
		err("%s: failed resubmitting urb, ret=%d, port=%d",
		    __FUNCTION__, ret, priv->dp_port_num);
	}

}

/* 
*  Digi Read INB Callback
*
*  Digi Read INB Callback handles reads on the in band ports, sending
*  the data on to the tty subsystem.  When called we know port and
*  port->private are not NULL and port->serial has been validated.
*  It returns 0 if successful, 1 if successful but the port is
*  throttled, and -1 if the sanity checks failed.
*/

static int digi_read_inb_callback(struct urb *urb)
{

	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct tty_struct *tty = port->tty;
	struct digi_port *priv = usb_get_serial_port_data(port);
	int opcode = ((unsigned char *)urb->transfer_buffer)[0];
	int len = ((unsigned char *)urb->transfer_buffer)[1];
	int port_status = ((unsigned char *)urb->transfer_buffer)[2];
	unsigned char *data = ((unsigned char *)urb->transfer_buffer)+3;
	int flag,throttled;
	int i;
	int status = urb->status;

	/* do not process callbacks on closed ports */
	/* but do continue the read chain */
	if (port->open_count == 0)
		return 0;

	/* short/multiple packet check */
	if (urb->actual_length != len + 2) {
     		err("%s: INCOMPLETE OR MULTIPLE PACKET, urb->status=%d, "
		    "port=%d, opcode=%d, len=%d, actual_length=%d, "
		    "status=%d", __FUNCTION__, status, priv->dp_port_num,
		    opcode, len, urb->actual_length, port_status);
		return -1;
	}

	spin_lock(&priv->dp_port_lock);

	/* check for throttle; if set, do not resubmit read urb */
	/* indicate the read chain needs to be restarted on unthrottle */
	throttled = priv->dp_throttled;
	if (throttled)
		priv->dp_throttle_restart = 1;

	/* receive data */
	if (opcode == DIGI_CMD_RECEIVE_DATA) {
		/* get flag from port_status */
		flag = 0;

		/* overrun is special, not associated with a char */
		if (port_status & DIGI_OVERRUN_ERROR)
			tty_insert_flip_char(tty, 0, TTY_OVERRUN);

		/* break takes precedence over parity, */
		/* which takes precedence over framing errors */
		if (port_status & DIGI_BREAK_ERROR)
			flag = TTY_BREAK;
		else if (port_status & DIGI_PARITY_ERROR)
			flag = TTY_PARITY;
		else if (port_status & DIGI_FRAMING_ERROR)
			flag = TTY_FRAME;

		/* data length is len-1 (one byte of len is port_status) */
		--len;

		len = tty_buffer_request_room(tty, len);
		if (len > 0) {
			/* Hot path */
			if (flag == TTY_NORMAL)
				tty_insert_flip_string(tty, data, len);
			else {
				for(i = 0; i < len; i++)
					tty_insert_flip_char(tty, data[i], flag);
			}
			tty_flip_buffer_push(tty);
		}
	}
	spin_unlock(&priv->dp_port_lock);

	if (opcode == DIGI_CMD_RECEIVE_DISABLE)
		dbg("%s: got RECEIVE_DISABLE", __FUNCTION__);
	else if (opcode != DIGI_CMD_RECEIVE_DATA)
		dbg("%s: unknown opcode: %d", __FUNCTION__, opcode);

	return(throttled ? 1 : 0);

}


/* 
*  Digi Read OOB Callback
*
*  Digi Read OOB Callback handles reads on the out of band port.
*  When called we know port and port->private are not NULL and
*  the port->serial is valid.  It returns 0 if successful, and
*  -1 if the sanity checks failed.
*/

static int digi_read_oob_callback(struct urb *urb)
{

	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct usb_serial *serial = port->serial;
	struct digi_port *priv = usb_get_serial_port_data(port);
	int opcode, line, status, val;
	int i;

	dbg("digi_read_oob_callback: port=%d, len=%d",
			priv->dp_port_num, urb->actual_length);

	/* handle each oob command */
	for(i = 0; i < urb->actual_length - 3;) {
		opcode = ((unsigned char *)urb->transfer_buffer)[i++];
		line = ((unsigned char *)urb->transfer_buffer)[i++];
		status = ((unsigned char *)urb->transfer_buffer)[i++];
		val = ((unsigned char *)urb->transfer_buffer)[i++];

		dbg("digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d",
			opcode, line, status, val);

		if (status != 0 || line >= serial->type->num_ports)
			continue;

		port = serial->port[line];

		if ((priv=usb_get_serial_port_data(port)) == NULL)
			return -1;

		if (opcode == DIGI_CMD_READ_INPUT_SIGNALS) {
			spin_lock(&priv->dp_port_lock);
			/* convert from digi flags to termiox flags */
			if (val & DIGI_READ_INPUT_SIGNALS_CTS) {
				priv->dp_modem_signals |= TIOCM_CTS;
				/* port must be open to use tty struct */
				if (port->open_count
					&& port->tty->termios->c_cflag & CRTSCTS) {
					port->tty->hw_stopped = 0;
					digi_wakeup_write(port);
				}
			} else {
				priv->dp_modem_signals &= ~TIOCM_CTS;
				/* port must be open to use tty struct */
				if (port->open_count
					&& port->tty->termios->c_cflag & CRTSCTS) {
					port->tty->hw_stopped = 1;
				}
			}
			if (val & DIGI_READ_INPUT_SIGNALS_DSR)
				priv->dp_modem_signals |= TIOCM_DSR;
			else
				priv->dp_modem_signals &= ~TIOCM_DSR;
			if (val & DIGI_READ_INPUT_SIGNALS_RI)
				priv->dp_modem_signals |= TIOCM_RI;
			else
				priv->dp_modem_signals &= ~TIOCM_RI;
			if (val & DIGI_READ_INPUT_SIGNALS_DCD)
				priv->dp_modem_signals |= TIOCM_CD;
			else
				priv->dp_modem_signals &= ~TIOCM_CD;

			wake_up_interruptible(&priv->dp_modem_change_wait);
			spin_unlock(&priv->dp_port_lock);
		} else if (opcode == DIGI_CMD_TRANSMIT_IDLE) {
			spin_lock(&priv->dp_port_lock);
			priv->dp_transmit_idle = 1;
			wake_up_interruptible(&priv->dp_transmit_idle_wait);
			spin_unlock(&priv->dp_port_lock);
		} else if (opcode == DIGI_CMD_IFLUSH_FIFO) {
			wake_up_interruptible(&priv->dp_flush_wait);
		}
	}
	return 0;

}

static int __init digi_init(void)
{
	int retval;
	retval = usb_serial_register(&digi_acceleport_2_device);
	if (retval)
		goto failed_acceleport_2_device;
	retval = usb_serial_register(&digi_acceleport_4_device);
	if (retval) 
		goto failed_acceleport_4_device;
	retval = usb_register(&digi_driver);
	if (retval)
		goto failed_usb_register;
	info(DRIVER_VERSION ":" DRIVER_DESC);
	return 0;
failed_usb_register:
	usb_serial_deregister(&digi_acceleport_4_device);
failed_acceleport_4_device:
	usb_serial_deregister(&digi_acceleport_2_device);
failed_acceleport_2_device:
	return retval;
}

static void __exit digi_exit (void)
{
	usb_deregister(&digi_driver);
	usb_serial_deregister(&digi_acceleport_2_device);
	usb_serial_deregister(&digi_acceleport_4_device);
}


module_init(digi_init);
module_exit(digi_exit);


MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");